Exercise habits are strongly related to body weight.In virtually all studies of large populations，the more active individuals weigh less.Weight-loss programs than incorporate exercise as well as diet are more successful than those that rely on6 diet7 alone.
注釋：
1.flexibility柔韌性
2.cardiorespiratory endurance心肺耐受力
3.aerobic有氧的，耗氧的
4.maximal cardiorespiratory endurance最大心肺耐受力
5.fatigue疲乏，衰弱
6.rely on依靠
7.diet節食
譯文
定期鍛煉計劃
定期鍛煉計劃的最大益處是能全麵增強身體素質。適當的鍛煉能提高肌肉的力量和持久性，改善人的身體結構和柔韌性，增加心肺的耐受力。氧氣的最大吸入量和心肺耐受力本身對大數人來說並不十分重要，重要的是人體穩定的能量消耗能力與這些性能的最高水平有直接關係。以每小時三英裏的慢速行走這個簡單的任務為例。這項行為需要消耗的能量大約是安靜狀態下生理代謝的3倍，對這些參加運動的人而言，每小時三英裏的行走需消耗他們最大體力的一半。一個定期鍛煉的中年人能達到的最高耗氧量是安靜狀態下的10到20倍，所以相同的行走隻需他最大耐受力的25%—30%。
一個人的最大心肺耐受力決定了他能采取多種活躍的方式來生活。如果嚐試一種超過自己承受能力的更大活動量的生活，這些人會長期感覺疲乏。
鍛煉習慣與體重密切相關。事實上對大量人群的所有研究都表明，越愛動的人體重越輕。鍛煉和節食相結合的減肥計劃比光依靠節食的計劃要有效得多。
(2)Exercise and Chronic Disease
運動與慢性病
Some evidence has suggested that regular exercise may help in the treatment or prevention of some chronic diseases.The control of tyreⅡ diabetes1，for example，appears to be aided by regular exercise.Exercise seems to improve the insulin2 sensitivity of cells，so that blood sugar3 can more readily be taken in and used as fuel.
A few reports have linked low physical activity with a higher risk of developing certain cancers，particularly colon cancer4.These results are intriguing5，but more work is needed to firmly establish that sedentary habits are an independent risk factor for cancer.